Convert loose FX_Create* functions into static methods

xfa/fgas/font/cfgas_gefont.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "xfa/fgas/font/cfgas_gefont.h"
 
 #include <memory>
 #include <utility>
@@ skipping 191 matching lines @@
     return false;
   return InitFont();
 }
 
 bool CFGAS_GEFont::LoadFontInternal(IFX_Stream* pFontStream, bool bSaveStream) {
   if (m_pFont || m_pFileRead || !pFontStream || pFontStream->GetLength() < 1)
     return false;
   if (bSaveStream)
     m_pStream.reset(pFontStream);
 
-  m_pFileRead.reset(FX_CreateFileRead(pFontStream, false));
+  m_pFileRead.reset(pFontStream->MakeSeekableReadStream());
   m_pFont = new CFX_Font;
   if (m_pFont->LoadFile(m_pFileRead.get()))
     return InitFont();
   m_pFileRead.reset();
   return false;
 }
 #endif  // _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 
 bool CFGAS_GEFont::LoadFontInternal(CFX_Font* pExternalFont) {
   if (m_pFont || !pExternalFont)
@@ skipping 229 matching lines @@
 
 int32_t CFGAS_GEFont::GetDescent() const {
   return m_pFont->GetDescent();
 }
 
 CFGAS_GEFont* CFGAS_GEFont::GetSubstFont(int32_t iGlyphIndex) const {
   iGlyphIndex = static_cast<uint32_t>(iGlyphIndex) >> 24;
   return iGlyphIndex == 0 ? const_cast<CFGAS_GEFont*>(this)
                           : m_SubstFonts[iGlyphIndex - 1];
 }